How to delete duplicate elements in php array

Array operations in PHP are very powerful, one of which is the ability to easily delete duplicate elements in an array. Therefore, this article will introduce you to the method of deleting duplicate elements in PHP arrays and its implementation principle.

1. array_unique() function

array_unique() is a built-in function in PHP that removes duplicate values ​​from an array and returns a new value after removing duplicate values. array.

Usage: array_unique($array)

Among them, $array is the array we want to duplicate.

2. Implementation principle

The implementation principle of array_unique() is very simple and clear. This function is implemented using two arrays. The first array is the original array. In this array, the element that appears for the first time will be retained, and subsequent repeated elements will be deleted. The second array is used to store elements that have already appeared. Whenever a new element is encountered, the element is added to the second array, and in the first array it is checked whether the element has already appeared, and if so, it is removed.

3. Example Demonstration

Below we will use an example to demonstrate how to use array_unique() to delete duplicate elements in a PHP array.

//Define an array with repeated elements
$array = array(1, 2, 3, 4, 4, 2, 5, 6, 7, 6 );

// Use array_unique() function to remove duplicates
$newArray = array_unique($array);

// Output the duplicated array
print_r($newArray );
?>

Running the above code, we get the following output:

Array
(

[0] => 1
[1] => 2
[2] => 3
[3] => 4
[6] => 5
[7] => 6
[8] => 7

)

From the output As can be seen from the results, the array_unique() function was used to successfully remove duplicate elements from the array.

4. Summary

Through the explanation of this article, we have learned how to delete duplicate elements in PHP array operations, and have mastered the implementation principles and specific operation methods. In the actual programming process, using the array_unique() function to delete duplicate elements can not only improve the execution efficiency of the code, but also effectively reduce the amount of code and improve the code quality.

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